Improvement in lifting-jacks



W. H. GREENWALT.

Improvement in Lifting-Jacks.

" No.120,511. 'Patentd Oct. -31, 1871.

gmmhw I UNITED STATES WILLIAM H. GREENWALT, OF STRIOKERSVILLE,PENNSYLVANIA.

IMPROVEMENT IN LlFTlNG-JACKS.

Specification forming part of Letters Patent No. 120,511, dated October31, 1871.

To all whom it may concern:

Be it kn own that I, WILLIAM H. GREENWALT, of Strickersville, in thecounty of Chester and State of Pennsylvania, have invented a new andvaluable Improvement in Carriage-Jacks; and I do hereby declare that thefollowing is a full, clear, and exact description of the constructionand operation of the same, reference being had to the annexeddrawingmaking apart of this specification, and to the letters andfigures of reference marked thereon.

Figure 1 of the drawing is a side view of my invention.

My invention has relation to an improvement in wagon jacks, the subjectwhereof has an adjustable standard sliding upward over the inclined faceof a stationary standard, and operated by means of a bent lever, which,being pivoted to the stationary standard, is coupled to the other bymeans of a toggle-link. My invention consists in the construction andnovel arrangement of the bent lever above referred to, and of a lockingroller journaled to the stationary standard by means of a stout pin, theobject being to obtain the maximum power of the lever with out waste,and to provide an effectual and convenient locking device which will notbe over come by the downward pressure on the adjustable standard whichsupports the weight to be lifted.

In the accompanying drawing, A represents a sill supporting a standard,B, having an inclined face, upon which slides an adjustable standard, B,having a correspondingly-i.nclined back, and constructed with a seriesof notches or steps, b, to hold axles of various heights. 0 O designateguiding-bands secured respectively to the stationary and adjustablestandards, and passing over the necks cl d of the same. D represents aJ-shaped lever, which has a long arm and is pivoted at the junction ofsaid arm with the curved part to the standard B by means of a pivot, dAttached to the end of said lever is a straight link, E, which ispivoted at its upper end to the adjustable standard B by means of apivot, d F indicates a strong roller journaled to the side of thestandard A obliquely above the pivot 01 In the drawing representing theparts in full outline the adjustable standard is shown as down, restingon the sill A. In this position the arm of the lever D stands upright,the lower end of the link E being on the side of the roller F oppositethe pivot al said link lying parallel or nearly parallel to the inclinedsurfaces of the standards B B. In order to raise the standard B thelever D is pressed down and is locked when the inner side of its curvetouches the roller F. This roller is arranged in such relation to thelever that, in order to efiectits function, the connected ends of thelever and link must fall on one side of a direct line running from thepivot 01 to the pivot 6?, while the roller is situated on the oppositeside. Otherwise a moderate pressure would throw the lever back to itsoriginal position. When the ends of the lever and link attain the pointabove described the roller F serves the double purpose of a lock and ofafulcrum, in its latter function relieving the strain of the pivot 01The locking device, being a roller, gives slightly to the pressure ofthe lever, making the same more rigid, and may be turned aroundaccording as it wears, so that the lever and link may always attain theproper locking position, as described.

What I claim as my invention, and desire to secure by Letters Patent,is-

The lever D, link E, slide B, and lock-roller F, constructed andarranged as described, in combination with the adjustable standard B ofa wagon-jack, as and for the purpose set forth.

In testimony that I claim the above I have hereunto subscribed my namein the presence of Witnesses GEO. H. WATSON,

WM. H. SIMPERS. (79)

